import java.util.Scanner;

/**
 * Created by 14229 on 2020/2/19.
 */
public class Test08 {
    public static void main(String[] args) {

        int[] arr ={21,19,12,39,46,76,23,92,37,54,25,74,20,13,53};
        int search = search(arr);
        System.out.println(search);
    }
    public static int search(int[] arr){
        Scanner sc = new Scanner(System.in);
        int i = sc.nextInt();
        int a = -1;
        for (int j = 0; j <arr.length ; j++) {
            if (arr[j]==i){
                a = j;
            }
        }
        return a;

    }
}
